Electrical contact device



Feb. 14, 1950 l R. s. THACKER 2,497,568

ELECTRICAL CONTACT DEVICE Filed Oct. 16, 1944 297 nl. ,if 'ff atenteclFeb. 14, i950 UNI-T ED `PrT1-E.`."l*-lfl`V OFFICE-`amino'miein;-oou'riflo'rilnnvlon' l RalphSffThackei'-, Windsorlls,Calif. "nmilictio ocfube's, isuiflser'iaiivd. 553,942

' 'Thisinventof basto dvvithfan fltr'calfcentact device and hasfpaiticular `freiee'ncetoa socket 4for a pin 1`type fco'ntact fdevi'ce.'{Ageneral object of theV invention lis to prov-ide fan inexpensive,simple and lhighlyfeioie'nt Contactv device particularly'iusefulonistrandedfcable. y

A' "Electrical Contact devices ithe' natur o'ts'ockets have beenmade'invariousinanners. "l-Iowever, the -usual fs'ocliet'foi receivingalpinmeniber involves aV lengitudin'allys'plit contact sleeve; lione endofwhich is 'operi' t6 rfcveth L'invvl'iil the other end is joinedi-tthe' lead line-'iorifvvire 'Such split sleevetype*socketsf'establish-limite'dcoritact With the pin and!Yin"nr'actoegftliereisa sbstantial voltage' drop" 'or yelectrical loss-Aacross" suchy connection.

-It' is a -general "Object of f tlisiinlention to Spiro# vide a'socket'-type eonnectorfin olvingfgenerally, a; plurality A'of' 'free orfloatinglfcontactfseginerits for 'engagingr the 15in; 'each 4of 'whichisf-r'ee toes-k' tablish alseparate and-most'ffective contactwiththe'prin. l

- Another*generalf'bjct offthe Vinventioniris Cto provide an lassemblyofi the' engaging-*Segments such-asV I have herinab'vef referred1 to'with means whereby the segments are yieldingly urgedi'nto effectivefengagement With' 'a pin A'Jar-rar'x'geel inlthe device. fInl accordancewith: 'Sniy Tinventionthe several segments Fare elongate V"men'ibers' fconnect-l ed 'directly v'vith-ftlle"'e'rn'is'f'of.y thelfst'ranclsfofe-acable. Springs rsurround the'ass'ernblyl ofis'egments bear-ingoneachfoneto urgelitinwardly intobearingengagement Withthe pin.

Another object' lof my 'i'nv'ention"is-'to provide a socket 1 contactdevice f-of 'thelgener al character hereinabove referred rto'vinffwnichthe-fseg'ments are carriedin'a -simple'sleeve Wliichvservesltorec'eivethe Send' portionofithe insulationon -afc'able` or' line 'connected' tothe'device 'i'ormi'n'gfwitl'ithe cable' a complete'f'operati-ve'struoturewhicli may* belused without iamplincationfor ar-ou-i'cl whichinsulating materialfcanf be re'ad'ilylfformed for molded to forma'carrierorbdy.

Another ob'ject'f of 'the fpresentinvention iscto provide va contactdevi'celfofltheigeneral character l the material." of the stra'ndsi :byIfbeing formed around thestrands through theapplicationfof eX-v ternalpressure. l

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- 125 ieferlredft'o'` in xavhichlthe- 'individualicontact'mem- HThevarious "objects landffeatures fofilmynvention Willbe'ifully-funderstood yfrom the following' y 2 detaileddescription-Riot:aLtypioal "preferred Cform andiapplicatonfof 'the invention throughoutwhich `description'- reference islm'aderto the'accompanyingf-'drawingsfin' which 'Fig.-1 is a topor'plan view-offanlelectrical contact device'orf plug embodying the*v present invention and `showing -ita'ssernbl'edi-on orinfcontact vvith- -a- .pair oielectrical cables.Fig-'"2" is lalongia tudinal detailed sectionalview of thefstructure ofi the' present 'i -inventionp'fbeing a View i taken as indicated by line2-'2"onFg'. I1. "Figlffisfan'fenlarged View of a part of the structurebeing-11a longitudinal'lsectional view of thecontact'parts shown appliedfover the ends :of f the .1 strands: or a' cable -iandishovvingl'fthe'retainingsleve vl`around the'Contactparts.l A Fig'L 4' is a.etransverse sectional viewtaken asindicated?by-linedkonllig 3. l Fig.Slis aitransverse fsectional 'viewi takenfas indicated by 1ine-5;-5ioniFig.-V :1, :andiFig: 6 is klan I enlarged detailed. sectionalvi'ew@off 'foneof Athe;:segmentsv taken @substantiallyr:asfiindioated :byline J Ii-L-l fon Fig; 3;."-Sho wingit,l'apartf'from z .the f other felements ofthefconstructicn.

The' 1 structure f'provided* by my @present -inven. tionflisf'appli'cable; Y generally-'nto socketsforA"receivingielectrical'connectors of ithe type. vFlor eXample,'itmaybeusedutoiadvantage'in a construction'lsuitable' forl receivinganelec'trical Aconnector-ici :.thefgeneral type :or rfcrm" which is1 setlforth my -companion'-:applicatiom entitled Electrical lconnectorfffiled i `on Aeven Adate herewith; SeialzNo; 558,94L4L4 v11n the:present-disclosme II 'set Y forth `a lsimple embodiment-:oftheinvention Wherein'ztl'iere :are two. units of fthe, invention:incorporated; in: a single-structure lIto, handle a vpairofvpinficontacts. -f'nipra'ctice ardevice may involve but one'-r unit fof 'r the invention: ior it vmayf involve nianyfunitsv and these :may/be`alike or they I.may beni: different-.sizesor shapes. The' constructionthat Ilz-:have provided may-be used-"ineach of the units'v` of '.tlie'fconstruction Aand, :therefore it is'fto be understood :that fthe`.following fde'scri'ptionicof one of l the ,.1 units may 'apply'equallywwell to' Athe erlly', a' contact"partfor-segment I'B on orconn'ection with eachzstrand of the cable'ywhich cena y tact-parts aresuch-fas toiform'a tubularassenibly fforlthe reception fofaiipinftypelelectricalzcontact;

v means ffl 3 'ivyieldinglyf furgingthe contactcparts2in--` Theconstruction that I have provided involves;` gen- When a standard cableC, which as I have shown in the drawings, is used, I remove theinsulation I5 of the cable from the end portion v of the cable so thatsuitable lengths of the strands 3 Y' the notches 3| therein creates veryhigh pressure S of the cable are exposed. The several strands which aresubstantially round in cross section,

being an assembly of fine wires, are separatedvv and the contact partsthat I have provided are applied thereto.

Each contact part or segment I0 is in the form of a straight tube. Inpractice I prefer to use simple round tubing of a size that willslidably receive a strand S` of the cable C and I prefer to form thetubes of a good electrical conducting material such as copper. Inaccordance with my invention I apply external pressure to the tube whileit is on the end of the strand S so that the tube is compressed onto thestrand and is formed so that it is segmental in cross sectionalconfiguration, as shown in Fig. 6. The desired pressure may be appliedby means of a die or forming device which gives the tube the desiredshape.

In the preferred form of the invention I apply pressure to the tube sothat the several wires of the strand S within the tube are pressed intointimate contact with each other and with the interior o'f the tube andthe tube is formed to have a concave inner wall 20, substantially iiatradial side walls 2|, and a convex outer wall 22. In practice I mayapply sucient pressure so that the wires of the strand in contact withthe interior of the tube are flattened against the tube and the severalwires are brought into contact with one another so that they aresubstantially polygonal or hexagonal in cross sectional configuration. 1I form the inner wall 2| of the contact to have a radius that willconform to that of the pin to be used with the device, and I form theouter wall 22 so it is substantially concentric with the inner wall. Thecircumferential extent of each contact part is governed by the numbervof strands and corresponding contact parts employed in theconstruction. For instance, where I have employed a cable with eightstrands, as illustrated in Fig. 4, each contact device extends aroundthrough an angle of about 45 degrees.-

In practice I proportion the several contact devices so that theyassemble into an annular body such as is shown in Fig. 4 which bodyforms a pin receivingv opening 25 somewhat smaller than the pin to beinserted in the device when the adjacent` contact parts are in contactwith each other. In practice I prefer to suitably dress the forwardinner cover of each contact part to facilitate insertion of a 'pin intothe assembly.

The means I3 provided for yieldingiy urging the contact parts I 0inwardly involves a plurality of annular spring elements surrounding theassembly of contact parts. Each contact part is provided in its outerwall at suitable points along its length with indentations or notches3|, and the notches of the several contact parts register formingannular channels or grooves around the assembly of contact parts toreceive or to accommodate the spring members 3|). In

the preferred form each spring member 3U is a helical spring arranged ina loop with its ends joined together forming what is commonly termed agarter spring. In the preferred construction the springs 30 and thenotches 3| are proportioned so that the spring seat in the notches anddo not project radially outward beyond the outer walls 22 of the contactparts. In some cases the springs may be merely applied aroundtheassembly without :being received into the contact parts.

The application of force or pressure to the exterior or outer part ofeach contact part to form or compressive force at the points where thenotches occur and, in effect, establishes a crimped condition in thestrands or between the strands and the contact tubes positivelypreventing disy placement of the contact tubes from the strands.

The sleeve II is somewhat longer than thev contact parts and the partsare arranged so that the assembly of .contact parts is located in theforward end portion of the sleeve. An inwardly projecting radial ange 4Uis provided at the forward end of the sleeve to form a stop or limitingshoulder for the forward end of the assembly-of` contact parts. The rearend portion of the sleeve projects inward beyond the assembly of contactparts and beyond the point from which the strands have been bared byremoval of insulation I5 so that the end portion of the body ofinsulation I5 on the cable C is carried within the sleeve. Thisrelationship of parts is clearly illustrated in Fig. 2 of the drawings.The structure formed by the assembly of contact parts and the sleeve IImay be used without any additional parts.

The body I2 when used is preferably a molded or cast body of insulatingmaterial which encases the sleeve and the end portion of the cable C. Inthe particular case illustrated there are two cables and the sleeveswith their assemblies of contact parts are molded or cast in side byside relation in the body I2. It will be apparent that by'havingprovided a sleeve around the assembly of contact parts, which sleeve hasthe inwardly turned flange 4U at its forward end and has engagement overthe forward end portion of the insulation I5 on the cable C, it is avery simple operation to mold a rbody of insulating material, such asrubber or the like, around the sleeve and cable without in any wayaffecting or complicating the other parts of the structure. It will benoted from an examination of Fig. 2 of the drawings that there is ashort length of exposed strands S between the end of the insulation I5and the assembly of contact parts giving slight longitudinal pla;7 oryieldability to the contact' parts.

From the foregoing description it will be ap- The clear-v contact with apin inserted in the assembly of contact parts. The springs surroundingthe assembly of contact parts act on each and every one of. the contactparts normally urging it inwardly and since there is no mechanical tiebetween the contact parts except through the springs and the cablestrands, each contact part is free to center and seat itself on theexterior of the pin or plug to establish a highly efficient seatingengagement or electrical contact.

Having described only a typical preferred form and application of myinvention, I do not wish to be limited or restricted to the specificdetails herein set forth, but wish to reserve to myself any variationsor modifications that may appear to those skilled in the art and fallwithin the scope of the following claims:

Having described my invention, I claim:

l. An electrical socket including a plurality of individual contactparts forming a tubular assembly to receive a pin and each having anopening to receive an electrical conductor, a yieldable elementsurrounding the assembly of contact parts to yieldably urge each oneinwardly, a sleeve surrounding the assembly and said elements, and abody of insulating material surrounding the sleeve.

2. An electrical socket including a plurality of individual contactparts forming a tubular assembly to receive a pin and each being a tubeadapted to be connected with an electrical conductor, a yieldableelement surrounding the assembly of contact parts to yieldably urge eachone inwardly, and a member surrounding and housing the assembly ofcontact parts.

3. In combination a stranded cable, a tubular contact on each strand ofthe cable, the contacts being arranged to form an annular socket, meansnormally yieldably urging the contacts inwardly, a sleeve around thecontacts, and a body around the sleeve, the body being formed ofinsulating material.

4. In combination a stranded cable, a tubular contact on each strand ofthe cable, the contacts being arranged to form an annular socket, meansnormally yieldably urging the contacts inwardly, and an insulatingmember around the contacts, each contact being shaped around the strandcontained therein to have a concave inner face.

5. In combination a stranded cable, a tubular contact on each strand ofthe cable, the contacts being arranged to form an annular socket, meansnormally yieldably urging the contacts inwardly, a sleeve around thecontacts, and a body of insulation around the sleeve, each contact beingtight on the strand contained therein and having a concave inner faceand substantially flat radial sides and a convex outer face concentricwith the inner face, there being notches in the outer faces of thecontacts, said means including an annular helical spring carried in thenotches.

6. In combination a stranded cable, a tubular contact on each strand ofthe cable, the contacts being arranged to form an annular socket, meansnormally yieldably urging the contacts inwardly, a sleeve around thecontacts, and a body of insulation around the sleeve, the sleeve havingan inwardly extending flange at the forward end of the receptacle formedby the contacts and having an inner end portion projecting beyond thesaid receptacle and over the cable.

7. In combination a stranded cable including conducting strands andinsulation over the strands except at their end portions, a tubularContact on the end portion of ea-ch strand of the cable, the contactsbeing arranged to form an annular socket, means normally yieldablyurging the contacts inwardly, and an insulating member surrounding thesocket formed by the contacts.

8. An electrical socket for use on a stranded cable including aplurality of individual tubular contacts each having a strand of thecable extending into it and all assembled to form a socket, each contacthaving an inwardly indented portion to grip the strand within it, and ayieldable member surrounding the assembly of contacts and held by thenotch portions of the contacts.

RALPH S. TI-IACKER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,759,567 Dibner May 20, 19301,936,469 Hill Nov. 21, 1933 2,083,379 Hill June 8, 1937 2,265,006 Rubelet al. Dec. 2, 1941 FOREIGN PATENTS Number Country Date 470,611 FranceJune 19, 1914

